Computer Science Education in Selected Countries from Sub-Saharan Africa
- Authors: Bainomugisha, Engineer , Bradshaw, Karen L , Ujakpa, Martin Mabeifam , Nakatumba-Nabende, Joyce , Nderu, Lawrence , Mduma, Neema , Kihoza, Patrick , Irungu, Annette
- Date: 2024
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440223 , vital:73758 , xlink:href="https://doi.org/10.1145/3643037"
- Description: Computer Science education in sub-Saharan Africa has evolved over the past decades. The number of institutions offering distinct undergraduate programs has grown, thus increasing the number of students enrolling in the computer science discipline. Several computer science degree programs have emerged with one of the objectives being to satisfy the growing demand for local talent and skills. In this paper, we provide a snapshot of the evolution of undergraduate computer science education in selected countries in Sub-Saharan Africa over the past 20+ years and an overview of the developments in computer science education and observed trends. The setup of educational institutions in Africa and the operational context requires unique modalities for the design and delivery of computer science education that meets the demands of the industry, amongst others. This paper provides insights into the best practices in the computer science curricula in the selected countries, as well as an overview of the pedagogical and delivery approaches to computer science education. The paper highlights case studies from institutions in the selected countries, namely Uganda, South Africa, Ghana, Tanzania, and Kenya with a consolidated summary of the current and emerging challenges and opportunities in all these countries. The paper concludes by providing persectives on the future landscape of computer science in Sub-Saharan Africa.Computer Science Education in Selected Countries from Sub-Saharan AfricaBy Engineer Bainomugisha, Makerere University, Uganda, Karen Bradshaw, Rhodes University, South Africa, Martin Mabeifam Ujakpa, Ghana Communication Technology University, Ghana, Joyce Nakatumba-Nabende, Makerere University, Uganda, Lawrence Nderu, Jomo Kenyatta University of Agriculture and Technology, Kenya, Neema Mduma, Nelson Mandela African Institution of Science and Technology, Tanzania, Patrick Kihoza, Mzumbe University, Tanzania and Annette Irungu, Jomo Kenyatta University of Agriculture and Technology, Kenya
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- Date Issued: 2024
Data Visualization of Budgeting Assumptions: An Illustrative Case of Trans-disciplinary Applied Knowledge
- Authors: Cuthbert, Carol E , Pearse, Noel J , Bradshaw, Karen L
- Date: 2024
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440236 , vital:73759 , xlink:href="https://doi.org/10.54808/JSCI.22.01.130"
- Description: Trans-disciplinary research combines different fields into new conceptual and methodological frameworks. In this study, the SECI model of knowledge creation, which consists of Socialization, Externalization, Combination, and Internalization conversion modes, is used to analyze the implementation of a structured budgeting visualization system by a trans-disciplinary team. Through applied research in implementing a global budgeting system, budgeting assumptions are made explicit through visualization, transforming the approach to the budgeting process and its accuracy. This visualization, in turn, is enabled by assumptions underlying revenue planning, business services and employee compensation, and a visual process. The system displays a stepped approach, indicated by icons, representing the tasks involved in the budget process. For example, the system requires uploading the previous year’s information, setting the assumptions, calculating the suggested figures based on assumptions, and amending the proposed outcome. As adapted by Rice and Rice (2005), SECI is applied as the socialization of tacit-to-tacit budgeting assumption knowledge is solidified during the design phase of this transformation exercise. The externalization phase, in which budgeting assumptions are transformed from tacit to explicit, is evidenced during the configuration phase of the new system. The systemic collaboration results in the explicit assumptions being collectively leveraged across the regions during and after the “go-live” phase of system development. Finally, the internalization phase involves the explicit assumptions being transformed into new tacit knowledge as the experts evolve new assumptions derived from the transformation process. Semiotics provides variance information through hue, with, for example, darker colours indicating higher variances. This trans-disciplinary communication provides the means for increased efficiency and effectiveness. The resulting budget framework is visually validated through a heatmap by comparing the budgeting accuracy and assumption complexity between the different regions where it was implemented. In summary, value is added in developing a new data visualization process, focusing on the role of budgeting assumptions and using planning process visualizations. This approach improves communication efficiency, effectiveness, and understanding of budgeting while enhancing accuracy.
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- Date Issued: 2024
Holding a mirror up to Academic Development through the HELTASA (un) conferencing methodology
- Authors: Williams, Sandra , Adams, Anthea , Geduld-van Wyk, Charlene , Muhuro, Patricia
- Date: 2024
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425705 , vital:72277 , xlink:href="https://doi.org/10.14426/cristal.v12iSI1.2117"
- Description: We, Academic Development (AD) practitioners, question whether AD's objective in South Africa (SA) as a'liberatory educational and social movement'to enhance educational quality for all students, is effectively pursued. AD practitioners often work on the fringes of the academy, fighting for relevance and legitimacy within an increasingly performative and managerialist academic culture. Despite innovative AD initiatives AD work is criticised for being unresponsive, unreflexive, conformist, and lacking theoretical, scholarly, and critical engagement. We use critical pedagogical praxis, particularly the constructs of critique, reflexivity, power, and self-reflection, to interrogate the continuous tension between AD intention and practice. Through (un) conference methodology, this auto-ethnographic account of individual and collective engagements, using the" holding the mirror up" metaphor, critically questioned the tension and misalignments between the AD mandate and practices. Although in a SA higher education context, this research could be beneficial to HE contexts globally, given the ubiquity of AD work.
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- Date Issued: 2024
Human–crocodile interactions in the western Solomon Islands: the importance of local data for reducing attacks on people
- Authors: Shankar, Aswani , Matanzima, Joshua
- Date: 2024
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439922 , vital:73720 , xlink:href="https://doi.org/10.1017/S003060532300176X"
- Description: Interactions between people and the saltwater crocodile Crocodylus porosus frequently occur on islands and in coastal regions. Saltwater crocodiles impact people's lives and livelihoods by attacking them, resulting in minor or serious injuries, and by interfering in people's foraging activities. Retaliation may include killing the crocodiles involved. To reduce such human–crocodile interactions, data about the occurrence of incidents are required. We present data on encounters with crocodiles and attacks on people in the Roviana Lagoon, Solomon Islands. Data includes time of incident, gender, age and activity of the victim, water conditions and what happened to the crocodile after the incident. We used a questionnaire to capture the details of incidents that occurred during 2000–2020 in the villages of Dunde, Baraulu, Nusa Hope and Kozou. Most incidents were in the evening, mostly involving women, and most victims were aged 20–39 years or ≥ 60 years. In all cases people were attacked while gleaning for shellfish in the mangroves. Attacks occurred irrespective of whether the water was clear or murky, and in all cases the crocodiles were not killed. Such site-specific data will facilitate the formulation of strategies for reducing negative interactions between people and crocodiles in this particular location. Although the saltwater crocodile is categorized as Least Concern on the IUCN Red List, research such as this provides data that can be used for promoting coexistence with and conservation of this species.
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- Date Issued: 2024
South African government responses to Trump's Global Gag Rule: Silence, ignorance, and avoidance
- Authors: Ndabula, Yanela , Macleod, Catriona I , du Plessis, Ulandi , Moore, Sarah-Ann
- Date: 2024
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441299 , vital:73875 , xlink:href="https://doi.org/10.1177/02610183241229046"
- Description: In 2017, Donald Trump signed the Protecting Life in Global Health Assistance (PLGHA), thereby reinstating the Global Gag Rule. The policy restricted all United States foreign funding from abortion-related activities. Little research reports the responses of recipients of this bilateral assistance. The study documents the South African government's responses to the PLGHA. We accessed Hansard parliamentary debates, interviewed four parliamentarians alongside one government official, and reviewed a USAID-funded initiative developed while the policy was in effect. We analysed the data using interpretive content analysis through a global social policy and gendered coloniality lens. Our research documents silence, ignorance, avoidance, and possible over-interpretation of the PLGHA within the South African government. The colonialist politics of global redistribution created the grounds for gendered regulation, resulting in a fundamental undermining of reproductive rights. Ironically, the solution – advocacy and parliamentarian briefing regarding sexual and reproductive issues – is generally led by civil society, the bodies weakened by the PLGHA.
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- Date Issued: 2024
Teaching comprehensive sexuality education in a traumatized society: recognizing teachers as sexual, reproductive, and mental health frontline workers
- Authors: Macleod, Catriona I , du Plesis, Ulandi
- Date: 2024
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441316 , vital:73876 , xlink:href=" https://doi.org/10.3389/feduc.2024.1276299"
- Description: Research on school-based sexuality education in South Africa, taught within Life Orientation (LO), has mainly focused on learners’ responses, how teachers approach the subject, and the curriculum content. Critiques have included heteronormative biases, an emphasis on danger, disease and damage, a reinforcement of gendered binaries, and the lack of pleasure or well-being discourses. In contrast, our research focused on the unexpected moments teachers experience, i.e., the ethical, emotional or psychological challenges they encounter in their interactions with learners.
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- Date Issued: 2024
Violence against women who sell sex in eastern and southern Africa: a scoping review
- Authors: Macleod, Catriona I , Reynolds, John H , Delate, Richard
- Date: 2024
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441380 , vital:73881 , xlink:href="https://doi.org/10.1177/15248380231160847"
- Description: Women who sell sex (WSS) are vulnerable to violence. We present a scoping review of the last decade of research on the prevalence and incidence of, factors associated with, and services regarding violence against WSS in Eastern and Southern African (ESA). A systematic search of various databases resulted in 20 papers being reviewed. Inclusion criteria, applied by the first two authors, were as follows: empirical papers, key research problem is violence against WSS, and conducted in ESA countries. The lifetime prevalence of violence revealed in the studies ranged from 21% to 82%. A pattern of generalized violence against WSS from paying clients, male partners, strangers, family members, friends/acquaintances, and the authorities emerged. Factors associated with violence included the context within which the sex work occurs, alcohol use, type of sex exchange interactions, and personal factors (low education, low income, marriage, youth, high client volume, time in sex work, forced sexual debut, and internalized sex work stigma). WSS seldom access services after violence. Evaluations of two programs, a woman-focused HIV intervention, and the Diagonal Interventions to Fast-Forward Reproductive Health project, showed improvements in gender-based violence services. Findings suggest that targeted programmes should be paired with improving general health services and focus on promoting collective agency among WSS.
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- Date Issued: 2024
Activated carbon-decorated polyacrylonitrile fibers and their porphyrin-immobilized composites for removal of methylene blue dye and Ciprofloxacin in water
- Authors: Oyim, James , Amuhaya, Edith K , Nyokong, Tebello
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:65077 , xlink:href="https://doi.org/10.1080/10601325.2023.2183868"
- Description: Photocatalyst adsorbents are an appealing group of materials for environmental applications. Herein, we study a new simple, inexpensive, yet very effective adsorbent photocatalyst based on porphyrin immobilized activated carbon-decorated polyacrylonitrile, InP(PAN/AC), for removal of methylene blue dye and Ciprofloxacin in water under Xe-lamp and sunlight irradiation (the latter for Ciprofloxacin only). Our results shed light on developing the most effective and sustainable adsorbent photocatalysts that can easily be industrialized due to the ease of preparation through electrospinning coupled with the readily available preparation materials. After five cycles, the InP(PAN/AC) maintained high methylene dye removal efficiency and structural integrity. Significantly, we propose the coordinated contribution of singlet oxygen and hydroxyl radical in the photodegradation process and highlight the importance of such an integrated system with adsorption and photodegradation capabilities for water treatment.
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- Date Issued: 2023
Agent-based model development of a complex socio-ecological system: Methods for overcoming data and domain limitations
- Authors: James, C. L , Bradshaw, Karen L
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440189 , vital:73755 , xlink:href="https://doi.org/10.1016/j.ecoinf.2023.102224"
- Description: Agent-based models (ABMs) are appropriate tools for modelling socio-ecological systems due to their ability to handle complexity. However, development of such models is often an intensive process. There are many tutorials on the general methods and steps in ABM development but there are not necessarily practical details on how to overcome certain challenges. Honeybush (Cyclopia spp.), a kind of fynbos vegetation found in the Western and Eastern Cape mountains, is an important ecological and agricultural product in South Africa. It is considered a complex system due to its variability and unpredictability. The honeybush tea industry faces the challenge of meeting emerging market demands while maintaining sustainable harvesting practices, in the midst of an uncertain future due to climate change. We created a prototype model, HoneybushModel, using the MARS framework, a C# multi-agent simulation toolkit. The model was validated using historic data. Whilst outlining the development processes used to create the Honeybush Model, this paper provides a methodology for the development of such models and demonstrates techniques for addressing data, domain and framework limitations. The implemented model also acts as a case study for similar systems that could be modelled using an ABM.
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- Date Issued: 2023
Agent-Based Modeling and Simulation for Transmission Dynamics and Surveillance of Dengue: Conceptual and Design Model
- Authors: Pascoe, Luba , Nyambo, Devotha G , Bradshaw, Karen L , Clemen, Thomas
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440200 , vital:73756 , xlink:href="https://doi.org/10.1109/AFRICON55910.2023.10293299"
- Description: African countries need to strengthen surveillance and control of arboviral diseases such as dengue due to increased outbreaks and spread of arboviruses. Climatic, socio-environment, and ecological variables influence the spread of dengue fever in Sub-Saharan Africa. This paper presents an Agent-Based conceptual and design model for dengue fever developed using the Multi-Agent Research and Simulation (MARS) framework. The study analyzes dengue fever's spatial distribution and identifies the causal relationship between the disease and its climatic and environmental variables. Agent-based modeling (ABM) was used to comprehend the spatial patterns of variation to determine the ecological association between the observed spatio-temporal variations in dengue fever. The domain and design model of an ABM for the surveillance of dengue fever is presented based on the Overview, Design Concepts, and Details (ODD) protocol. Model input parameters and input data for the study area are also presented. The dengue ABM can be adopted and reused for modeling other diseases and other complex problems from different domains while ensuring that their unique characteristics and appropriate modifications are considered to ensure the model's validity and relevance to the new context.
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- Date Issued: 2023
An Exploration of Flow Control Using Machine Learning and Computational Fluid Dynamics
- Authors: Bradshaw, Karen L , Cornfield Matthew
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440211 , vital:73757 , xlink:href="https://doi.org/10.59200/ICARTI.2023.017"
- Description: Although numerous studies relating to computational fluid dynamics and machine learning have been conducted in relation to automotive development, the majority focus on either early development using completed 3D models, or the final testing stages of development, or machine learning accelerated computational fluid dynamic simulations. While this approach is helpful in software development and simulation, it is not easily adaptable to automotive design where the final model is constantly changing and being modified. Consequently, the aim of this study is to propose a method for conducting computational fluid dynamics and machine learning concurrently to accelerate the development process. The proposed method is used to design and improve the aerodynamic efficiency of an object. The approach focuses on developing, implementing, and comparing machine learning models capable of generating optimised three-dimensional objects with the required geometry to direct airflow paths required in applications such as pressure generation, as needed for both active and passive flow control. The study concludes that both decision tree regression and long short-term memory (LSTM) autoencoder models could be used to optimise the aerodynamic efficiency of solid bodies, but that the LSTM autoencoder performs better overall. An undesirable effect of the shape optimisation is an overall reduction in shape size as optimization increases.
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- Date Issued: 2023
Asymmetrical zinc phthalocyanine conjugated to various nanomaterials for applications in phototransformation of organic pollutants and photoinactivation of bacteria
- Authors: Mgidlana, Sithi , Openda, Yolande Ikala , Nyokong, Tebello
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/360344 , vital:65081 , xlink:href="https://doi.org/10.1016/j.molstruc.2022.134850"
- Description: Zinc phthalocyanine (ZnPc) complexes are linked to metallic nanoparticles covalently via amide and ester bonds. The photocatalytic activity of the conjugates of ZnPc complexes with NiWO4, Ag2WO4, CoWO4 and Ag-Fe3O4 nanoparticles are evaluated for photodegradation of methylene blue, tetracycline, and dibenzothiophene. The photocatalytic efficiencies of the prepared phthalocyanine complexes increased in the presence of nanoparticles. This work also reports on the photodynamic antimicrobial chemotherapy activity of these materials against Staphylococcus aureus (S. aureus) bacteria. The results indicate that Ag2WO4 based nanoconjugates exhibit high antimicrobial activity with higher log reduction compared to NiWO4, CoWO4 and Ag-Fe3O4 based materials.
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- Date Issued: 2023
Best practices in the use and exchange of microorganism biological control genetic resources
- Authors: Mason, Peter G , Hill, Martin P , Smith, David , Silvestri, Luciano C , Weyl, Philip S R , Brodeur, Jacques , Vitorino, Marcello Diniz
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417927 , vital:71495 , xlink:href="https://doi.org/10.1007/s10526-023-10197-3"
- Description: The Nagoya Protocol actions the third objective of the Convention on Biological Diversity and provides a framework to effectively implement the fair and equitable sharing of benefits arising out of the use of genetic resources. This includes microorganisms used as biological control agents. Thus biological control practitioners must comply with access and benefit-sharing regulations that are implemented by countries providing microbial biological control agents. A review of best practices and guidance for the use and exchange of microorganisms used for biological control has been prepared by the IOBC Global Commission on Biological Control and Access and Benefit-Sharing to demonstrate commitment to comply with access and benefit-sharing requirements, and to reassure the international community that biological control is a very successful and environmentally safe pest management strategy that uses biological resources responsibly and sustainably. We propose that best practices include the following elements: collaboration to facilitate information exchange about the availability of microbial biological control agents and where they may be sourced; freely sharing available knowledge in databases about successes and failures; collaborative research with provider countries to develop capacity; and production technology transfer to provide economic opportunities. We recommend the use of model concept agreements for accessing microorganisms for scientific research and non-commercial release into nature where access and benefit-sharing regulations exist and where regulations are not restrictive or do not exist. We also recommend a model agreement for deposition of microbial biological control agents into culture collections.
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- Date Issued: 2023
Co phthalocyanine mediated electrochemical detection of the HER2 in the presence of Au and CeO2 nanoparticles and graphene quantum dots
- Authors: Centane, Sixolile , Nyokong, Tebello
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/360372 , vital:65083 , xlink:href="https://doi.org/10.1016/j.bioelechem.2022.108301"
- Description: In this work, cobalt tetra phenoxy acetic acid phthalocyanine (CoTAPc) is investigated as an electron mediator, immobilization platform for an HB5 aptamer and to enhance the electrochemical signal for the detection of human epidermal growth factor receptor 2 (HER2). Furthermore, the CoTAPc was combined individually with sulphur/nitrogen doped graphene quantum dots (SNGQDs), gold nanoparticles (AuNPs) and cerium oxide nanoparticles (CeO2NPs), on a glassy carbon electrode (GCE) via sequential adsorption. The CoTAPc and SNGQDs were also π-π stacked, used for electrode modification similarly to the rest of the other surfaces and applied towards the electrochemical detection of HER2. The designed sensors were characterized using electrochemical impedance spectroscopy (EIS). The designed aptasensors showed detection limits as low as 6.0 pg/mL. The real life applicability of the designed aptasensors was tested in human serum samples. The aptasensors showed great storage stability, sensitivity and specificity towards HER2, implying great potential for applications in early diagnosis of breast cancer.
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- Date Issued: 2023
Combination of photodynamic antimicrobial chemotherapy and ciprofloxacin to combat S. aureus and E. coli resistant biofilms
- Authors: Openda, Yolande Ikala , Nyokong, Tebello
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/360384 , vital:65084 , xlink:href="https://doi.org/10.1016/j.pdpdt.2022.103142"
- Description: Photodynamic antimicrobial chemotherapy (PACT) coupled with an antibiotic, ciprofloxacin (CIP), was investigated using two indium metallated cationic photosensitizers, a porphyrin (1) and a phthalocyanine (2). Applying PACT followed by the antibiotic treatment led to a remarkable reduction in the biofilm cell survival of two antibiotic-resistant bacterial strains, S. aureus (Gram-positive) and E. coli (Gram-nenative). Treating both bacteria strains with PACT alone showed no significant activity at 32 µM with 15 min irradiation, while CIP alone exhibited a minimum biofilm inhibition concentration (MBIC) at 4 and 8 µg/mL on S. aureus and E. coli, respectively following 24 h incubation. The combined treatment resulted in the complete eradication of the matured biofilms with high log10 reduction values of 7.05 and 7.20 on S. aureus and E. coli, respectively, at low concentrations. It was found that 15 min PACT irradiation of 8 µM of complexes (1 and 2) combined with 2 µg/mL of CIP have a 100% reduction of the resistant S. aureus biofilms. Whereas the total killing of E. coli was obtained when combining 8 µM of complex 1 and 16 µM of complex 2 both combined with 4 µg/mL of CIP.
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- Date Issued: 2023
Comparative situational analysis of comprehensive abortion care in four Southern African countries
- Authors: Macleod, Catriona I , Reuvers, Megan , Reynolds, John H , Lavelanet, Antonella , Delate, Richard
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441199 , vital:73865 , xlink:href="https://doi.org/10.1080/17441692.2023.2217442"
- Description: We report on a comparative situational analysis of comprehensive abortion care (CAC) in Botswana, Eswatini, Lesotho and Namibia. We conducted systematic literature searches and country consultations and used a reparative health justice approach (with four dimensions) for the analysis. The following findings pertain to all four countries, except where indicated. Individual material dimension: pervasive gender-based violence (GBV); unmet need for contraception (15−17%); high HIV prevalence; poor abortion access for rape survivors; fees for sexual and reproductive health (SRH) services (Eswatini). Collective material dimension: no clear national budgeting for SRH; over-reliance on donor funding (Eswatini; Lesotho); no national CAC guidelines or guidance on legal abortion access; poor data collection and management systems; shortage and inequitable distribution of staff; few facilities providing abortion care. Individual symbolic dimension: gender norms justify GBV; stigma attached to both abortion and unwed or early pregnancies. Collective symbolic dimension: policy commitments to reducing unsafe abortion and to post-abortion care, but not to increasing access to legal abortion; inadequate research; contradictions in abortion legislation (Botswana); inadequate staff training in CAC. Political will to ensure CAC within the country’s legislation is required. Reparative health.
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- Date Issued: 2023
Contrasting effects of climate change on the invasion risk and biocontrol potential of the invasive Iris pseudacorus L. between Northern and Southern Hemisphere
- Authors: Minuti, Gianmarco , Coetzee, Julie A , Stiers, Iris
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423329 , vital:72048 , xlink:href="https://doi.org/10.1016/j.biocontrol.2023.105290"
- Description: Iris pseudacorus is both a prized ornamental and an invasive aquatic plant that tends to grow dense monospecific stands, displacing the local vegetation and altering the hydrology of freshwater ecosystems. Originally from Europe, this species has historically invaded North America, China and Japan, and more recently spread through Argentina, South Africa and Australasia, where it is now a target for biological control. Field surveys within its native range have led to the selection of three candidate biocontrol agents. Prioritizing the best candidates for different regions constitutes a critical step, which could save significant time and resources before further cost-intensive experimental studies are conducted. Climate change is seldom taken into consideration in the prioritization process. In this regard, climatic suitability can be used to model the potential distributions of weeds and their candidate agents, both in space and time, thus allowing to identify areas at risk of invasion and predict where agents will be able to establish long-term. Accordingly, the objectives of this work were (i) to predict I. pseudacorus invasions and range shifts in the context of climate change; (ii) to identify wetland areas most at risk of invasion under present and future climatic conditions; and (iii) to prioritize the best suite of candidate biocontrol agents for different invaded ranges, worldwide. To do so, we modelled the present and future (2040–2060) climatic suitability of I. pseudacorus and its candidate agents using the software MaxEnt. Our results highlight a clear distinction between predictions for the Northern and Southern Hemispheres. In North America and eastern Asia, the area climatically suitable for I. pseudacorus is expected to increase and shift northwards. As for its biocontrol agents, very low suitability is predicted across these regions, further decreasing under future climatic conditions. On the other hand, climatically suitable areas for the plant in South America, southern Africa and Australasia are predicted, on average, to reduce in response to climate change. A decrease in climatic suitability is also expected for its candidate biocontrol agents which, however, would still maintain a significant range overlap with their host. These results can be used to prioritize areas most at risk of invasion and identify which combination of candidates could potentially provide the best level of control across different invaded ranges.
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- Date Issued: 2023
Declines in Livestock Numbers Accompany Cropping Deagrarianisation Processes in the Eastern Cape, South Africa
- Authors: Shackleton, Charlie M , Ntshudu, Monde
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/402248 , vital:69834 , xlink:href="https://doi.org/10.3390/land12091735"
- Description: Deagrarianisation amongst smallholder farmers is a growing phenomenon globally, driven by a complex array of context-specific and higher-scale factors. Most research has focused on declines in arable cropping, with relatively little regard to the deagrarianisation dynamics associated with livestock ownership, yet the two are often linked through the need for draught power for ploughing. Here, we report on a survey of 293 rural households in 10 rural villages in the Eastern Cape province, South Africa, where we ascertained whether ownership of cattle, goats, sheep and pigs had changed over the previous 15 years and what were the underlying reasons for any changes at both village- and household-scale. The majority felt that there had been a decline in the number of households keeping livestock and the number of animals in the village. Additionally, a clear majority of owners for each type of livestock stated that their households currently have fewer animals than 15 years ago. The main reasons for declines were that their animals had died due to drought or disease, theft, or they had sold them because of financial needs. There was a positive association between the keeping of cattle and field cultivation. Despite these general declines, two-thirds of households currently without livestock wished that they had some, primarily for use in cultural ceremonies/rituals or for income. This study shows the deagrarianisation processes in the region also apply to the livestock sector despite the significance of livestock in the local Xhosa culture. This study highlights the multifaceted nature of deagrarianisation in communal tenure systems.
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- Date Issued: 2023
Development of a translation device for axiological-semantic density in political news articles: Wording and charging
- Authors: Siebörger, Ian , Adendorff, Ralph D
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/385311 , vital:68006 , xlink:href="https://doi.org/10.1515/text-2020-0156"
- Description: The concept of axiological-semantic density from Legitimation Code Theory (LCT) is extremely helpful in analysing political knowledge-building, as it describes the strength of relations between various people, political stances and moral judgements, enabling these to be positioned in relation to each other. We present a multi-level translation device designed to identify strengths of axiological-semantic density in political news articles from the Daily Sun, South Africa’s most popular tabloid newspaper. This translation device was devised through analysis of selected texts from a corpus of 516 articles published between January and June 2015. It was developed through a collaborative process involving the first author and a team of student research assistants. The final translation device has five tools, of which two, the wording and charging tools, are described in this article, and then illustrated using an example analysis of a Daily Sun political news article. Both tools reveal insights into South African political discourses and ways in which axiological-semantic density can be enacted in future research. Making axiological-semantic density visible using such a translation device also has practical applications in assisting readers to understand the ways in which publications such as the Daily Sun position political parties, enabling them to engage more constructively in discussions on the country’s future.
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- Date Issued: 2023
Distribution and impact of the native South African wasp, Megastigmus transvaalensis (Hussey, 1956)(Hymenoptera: Torymidae) on the invasive Schinus terebinthifolia Raddi (Anacardiaceae) in South Africa
- Authors: Mangenlele, Nwabisa L , Martin, Grant D
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416841 , vital:71390 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v31_n1_a12"
- Description: Schinus terebinthifolia Raddi (Anacardiaceae) (Brazilian pepper tree) is a tree native to subtropical South America that was introduced into South Africa as an ornamental plant. Globally, it is regarded as one of the world’s worst invasive trees. In South Africa the tree has acquired a native seed-feeding wasp, Megastigmus transvaalensis (Hussey, 1956) (Hymenoptera: Torymidae). The wasp’s native hosts are from the Searsia F.A. Barkley genus (Anacardiaceae), but it has expanded its host range to form a new association with both S. terebinthifolia and its close relative Schinus molle L. (Anacardiaceae). In order to quantify the seed predation by M. transvaalensis on S. terebinthifolia seeds, tree populations were surveyed across the Eastern Cape and KwaZulu-Natal provinces. The wasp was present at 99% of the S. terebinthifolia populations with an average of 22% of the seeds being destroyed. In the Eastern Cape province, the highest seed damage occurred at the start of the winter months, when about 35% of seeds were damaged. This fell to less than 12% in spring and summer when the plants were flowering. Megastigmus transvaalensis was found at nearly all the S. terebinthifolia populations in South Africa, but due to the limited number of predated seeds it is unlikely to reduce population sizes or curb the spread of the invasive alien tree in South Africa.
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- Date Issued: 2023